
def print_xh_50():
    print('*'*50)

li=['alex', 'eric', 'rain']

new_li = "_".join(li)

print(new_li)
print_xh_50()

lens = len(li)

li.append('seven')
print(li)
li.insert(0,'Tony')
print(li)
li[1] = 'Kelly'
print(li)
li.remove('eric')
print(li)
del_ele = li.pop(1)
print(del_ele)
print(li)
li.reverse()
print(li)
for index in range(len(li)):
    print(index)

for index, item in enumerate(li):
    print(index, item)

for x in li:
    print(x, end = " ")
